The invention relates to a culture flask for cultivating cells, tissues or microorganisms.
Culture flasks (also termed “cell culture flasks”) are used in the laboratory to grow and obtain cells, tissues or microorganisms. They have a flat, substantially rectangular flask body with a bottom wall, cover wall and side walls that delimit a culture chamber. The top side of the bottom wall is a growth surface for cells, tissue or microorganisms. A flask neck with a lid projects to the outside from a narrow, front side wall. When used, the large bottom wall of culture flasks is normally placed on a horizontal base. The distance between the even bottom wall and the even cover wall of the culture flask is termed the height or thickness. When stacked, culture flasks can be arranged in a space-saving manner in an incubator that provides the climate for growing the cells, tissue or microorganisms. The lid can frequently be moved from a closed to a ventilation position, or is designed as a filter lid to ensure an exchange of gas between the incubator and culture chamber in the flask body.
Cells, tissue or microorganisms can be removed from the culture flask by means of a serological pipette, scraper or cannula that is inserted from the outside through the flask neck into the culture chamber toward the growth surface. Nutrient medium is also pipetted into or out of the culture flask through the flask neck by means of the serological pipette. These tasks are difficult, especially when they are performed at a sterile bench while the user is wearing protective clothing.
At a distance from the bottom wall, the bottle neck is connected to the margin of an opening in the side wall to prevent fluid from sloshing out of the culture chamber when the culture flask is opened. The opening is therefore delimited at the bottom by the distance between the bottle neck and the bottom wall, and at the top by the straight-line joint edge along which the top margin of the side wall is connected to the cover wall. To make it easier to access the growth surface with a serological pipette or a scraper, culture flasks are known that have a flask neck that is inclined toward the growth surface at a sharp angle. It is difficult for the serological pipette or the scraper to reach, in particular, the rear corners of the growth surface due to the edge of the top margin of the opening. Gliding the serological pipette or scraper along this edge is in fact associated with greater resistance than gliding along the smooth surface of the cylindrical flask neck.
EP 0 743 362 B1, the entire contents of which is incorporated herein by reference, describes a laboratory flask comprising a flask body that has a circular opening in a front side wall. An elongated annular flask neck with an inner and outer cylindrical wall extends outward from the margin of the opening. Part of the inside of the flask neck is arranged above the cover wall of the flask body. The flask neck has a pendant filling wall which closes the gap between the inside of the flask neck and the cover wall close to the front side wall. With this laboratory flask, access to the growth surface is limited by the filling wall at the top margin of the opening.
WO 2006/099127 A1, the entire contents of which are incorporated herein by reference, describes a cell culture flask comprising a flask body that serves as a cell culture chamber. The cell culture chamber is delimited by a bottom tray with a rigid surface and by a cover wall, the bottom tray and cover wall being connected to each other at side and end walls. In at least one opening, there is an angled flask neck, and at least one screw-on lid is aligned with the opening of the flask neck. In addition to the angled flask neck, the bottom wall and cover wall have recesses that rise and fall toward the flask neck so that no liquid remains captured in the corners. The angled flask neck improves the access to the cell culture chamber by a pipette, scraper or cannula. In addition, the rising and falling recesses provide free space for the lid so that it does not collide with a neighboring cell culture flask in a stack. The flask neck is preferably arranged at a corner of the cell culture flask so that the cell culture surface can be larger.
Against this background, an object of the invention is to provide a culture flask that makes it easier for a serological pipette, scraper, cannula or other elongated device to access the growth surface on the bottom wall for adding or removing material.